We had a system hiccup, a customer was super pissed because the CC machine was down. He started yelling at the cashier where he was -- 16 years old and quiet as a mouse. Our new manager stepped in right away and said 'sir I'm going to need you to take a deep breath and think about the situation. You are yelling at a girl who in no way caused or profits off of this malfunction. ' (paraphrasing I was a few stands over) and it worked. Dude even apologized to both of them. Customer whisperer!!